The present invention relates to a method for the preparation of highly heat-resistant relief structures by applying radiation-sensitive soluble polymer precursor stages in the form of a film or a foil to a substrate; irradiating the film or the foil through negative patterns with actinic light or by deflecting a light, electron or ion beam; removing the non-irradiated portions of the film or foil; and, optionally, subsequent annealing, as well as to the use of relief structures prepared in this manner.
A method of the type mentioned for the preparation of relief structures on the basis of polymers is known from German Patent 2 308 830 and its corresponding U.S. Pat. No. 3,957,512. According to this method, polyaddition or polycondensation products of polyfunctional carbocyclic or heterocyclic compounds, &lt; . . . &gt;, with diamines, diisocyanates, bisacid chlorides or dicarboxylic acids &lt; carrying radiation-sensitive radicals &gt; are used as soluble polymer precursor stages. The compounds which carry radiation-sensitive radicals contain two carboxyl, carboxylic-acid chloride, amino, isocyanate or hydroxyl groups suitable for addition or condensation reactions and, partly, &lt;&lt; . . . &gt;&gt;, radiation-reactive groups bound &lt;&lt; in ortho- or peri-position thereto &gt;&gt; to carboxyl groups in ester fashion. The diamines, diisocyanates, bis-acid chlorides and dicarboxylic acids to be reacted with these compounds have at least one cyclic structure element.
The soluble polymer precursor stages are cross-linked in the irradiation and are thereby converted into insoluble intermediate products. These intermediate products are subjected to cyclization in the annealing, with highly heat-resistant polymers of the following classes of materials being formed in the process: Polyimides, polyamidimides, polyester imides, poly-1,3-quinazoline-2,6-diones, polyisoindoloquinazoline diones, poly-1,3-oxazine-6-ones and polybenz-1,3-oxazine-2,4-diones.